Many mobile devices are configured to utilize Universal Integrated Circuit Cards (UICCs) that enable the mobile devices to access services provided by Mobile Network Operators (MNOs). In particular, each UICC includes at least a microprocessor and a read-only memory (ROM), where the ROM is configured to store an MNO profile that a mobile device can utilize to register and interact with an MNO. Typically, a UICC takes the form of a small removable card (commonly referred to as a Subscriber Identity Module (SIM) card) that is configured to be inserted into a UICC-receiving bay included in a mobile device. In more recent implementations, however, UICCs are being embedded directly into system boards of mobile devices. These embedded UICCs (eUICCs) can provide advantages over traditional SIM cards, e.g., an eUICC can store a number of MNO profiles—also referred to herein as “electronic Subscriber Identity Modules (eSIMs)”—and can eliminate the need to include UICC-receiving bays in mobile devices. Moreover, eSIMs can be remotely provisioned to mobile devices, which can substantially increase the overall flexibility when users purchase mobile devices, migrate their phone numbers to different MNOs, and the like.
Despite the various advantages provided by eUICCs and eSIMs, certain operating flexibility limitations have yet to be addressed. One limitation, for example, is that conventional approaches dictate that a given mobile device should be a member of only one trust circle, e.g., a trust circle associated with an MNO with which the mobile device is configured to interface. According to some approaches, an eUICC of a mobile device can be a member of the trust circle by storing one or more digital certificates associated with a Certificate Authority (CA) that serves as a root of the trust circle. Notably, as different MNOs/regions are associated with a wide variety of trust circles that are substantially distinct from one another, restriction of the eUICC of the mobile device to a single trust circle membership can be problematic with respect to the overall operating flexibility of the eUICC. For example, when a user seeks to install a new eSIM onto the eUICC—e.g., an eSIM for an MNO in a foreign country—and the eSIM/MNO are associated with a trust circle of which the eUICC is not a member, the user is unable to utilize the functionality that the eSIM could otherwise provide. Consequently, the overall operating flexibility of the mobile device remains limited, which can degrade the user's overall satisfaction.